机动车蒸发排放VOCs的SOA生成潜势和机制研究

近年来，我国机动车保有量持续增加，机动车相关的污染物加剧了我国大气复合污染的态势。随着我国机动车尾气排放标准的不断加严，机动车蒸发排放已成为人为源VOCs的主要来源之一，且其大气氧化过程具有较高的二次有机气溶胶（SOA）生成潜势。然而，目前针对我国机动车蒸发排放源的SOA生成研究较少，复合污染条件对其SOA生成的影响认识尚且不足。本项目拟利用30m3室内烟雾箱系统研究机动车蒸发排放VOCs的SOA生成潜势和二次转化机制，量化关键组分对SOA的贡献，并阐述其SOA生成机制和组分间的协同效应机制；探究颗粒物种子、NOx、SO2和NH3等复合污染条件对SOA生成的影响机制，评估复合污染条件下机动车蒸发排放源对SOA和PM2.5的贡献，为我国大气污染防治和协同减排决策提供科学依据。

In recent years, vehicle ownership in China has increased rapidly, and vehicle-related pollutants have exacerbated the severity of air pollution complex in China. With the implementation of tailpipe exhaust emission control measures, vehicular evaporation emissions have become one of the main sources of anthropogenic VOCs, and have a high SOA formation potential during the atmospheric oxidation process. However, there are few studies on secondary organic aerosol (SOA) formation directly from vehicular evaporation in China, and the influence of complex pollution conditions on SOA formation is still insufficiently understood. In this study, formation potential and mechanism of SOA from vehicular evaporation emissions VOCs are investigated using the 30m3 indoor smog chamber. The SOA formed from important precursors are quantified, then the corresponding mechanism for SOA formation and the synergistic effect between precursors are investigated. Aiming at the current situation of air pollution complex in China, the effect mechanism of coexisting seed particles, NOx, SO2 and NH3 on SOA formation is studied. At last, the contribution of vehicle evaporative emissions to SOA and PM2.5 is evaluate under complex pollution conditions, which will provide scientific information for formulating relevant policies of air pollution prevention and coordinated emission reduction control in China.